Issue#219: update SN76489 on leading edge /WE as well as polling.

stardot · Jan 19, 2024 · 24f41ba · 24f41ba
1 parent 1585826
commit 24f41ba
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/src/sysvia.c b/src/sysvia.c
@@ -84,13 +84,18 @@ static void sysvia_update_sdb()
 
 static void sysvia_write_IC32(uint8_t val)
 {
+    uint8_t oldIC32 = IC32;
+
         if (val & 8)
            IC32 |=  (1 << (val & 7));
         else
            IC32 &= ~(1 << (val & 7));
 
         sysvia_update_sdb();
 
+        if (!(IC32 & 1) && (oldIC32 & 1))
+            sn_write(sdbval);
+
         scrsize = ((IC32 & 0x10) ? 2 : 0) | ((IC32 & 0x20) ? 1 : 0);
 
     log_debug("sysvia: IC32=%02X", IC32);